Hypnic Jerks, Major Depressive Disorder, and Antidepressant Use: A Possible Relationship

The term hypnic jerks (also known as sleep starts or hypnagogic jerks) refers to a physiological phenomenon that accompanies sleep-wake transitions and can occur in healthy individuals of any age. Various physiological and stressful stimuli can precipitate hypnic jerks and contribute to their frequency and amplitude, e.g., stress, fatigue, stimulants like caffeine, and certain medications. Hypnic jerks are usually benign, but they can be intensified in certain situations, interfering with sleep onset and causing insomnia. Here we reported the case of a patient who suffered from intensified hypnic jerks that led to the development of major depressive disorder. Although the depressive symptoms improved on escitalopram 20 mg, the hypnic jerks increased significantly. Clonazepam was found to be very effective in reducing the hypnic jerks and stabilizing his condition.


Introduction
Hypnic jerks, sleep start or hypnic myoclonia are a physiological, non-periodic and abrupt myoclonic muscle contraction for almost all body muscles that occurring mainly on falling asleep.These physiological phenomena experienced by up to 70% of the adult population sometime in their life [1].
They presumably arise from sudden descending volleys that originate in the brainstem reticular formation and are activated by the instability of the system at the transition between wake and sleep [2].
They are associated with an autonomic activation, resulting in tachycardia, tachypnoea, and sudomotor activity described as a shock or falling feeling [3].Hypnic jerks may be exacerbated during stressful conditions occurring during a normal part of sleep onset [4].These stressful conditions that may cause hypnic jerks include fatigue, stress, sleep deprivation, vigorous exercise, and stimulants like caffeine and nicotine [5].
Although they are generally considered a benign condition, they rarely require investigation or treatment.If very severe, they can cause sleep-onset insomnia, a condition known as excessive fragmentary hypnic myoclonus [2].which is listed as a proposed sleep disorder in the ICSD classification (ASDA, 2005).
However, these are benign phenomena, but they need to be treated if they interfere with one's sleep or led to a significant reduction in the quality of life [6].

Case Presentation
A 31-year-old male, employee patient, had come to our outpatient department of psychiatry at Saudi German Hospital, Riyadh, Saudi Arabia.He was complaining of persistent sadness of mood and decreased interest in daily activities for almost 4 years.He also started remaining withdrawn, would not find pleasure in his usual social activities, which he used to like previously.His appetite decreased and he lost some of his wt.However, there was no history of death wishes, suicidal attempt or any self-harm behaviour.The patient attributed his symptoms to the sleep problem that he has a 2 year prior to having those symptoms.He reported a recurring and sudden muscle contractions of his whole-body, exclusively at the sleep onset, that would wake him up, followed by difficulty in falling back to sleep.It was associated with palpitation, tens feeling and excessive worry of being not able to sleep again.He would have fatigability the day after that affected his work performance.No history of snoring, breath cessation, excessive dreams, sleep walking or talking.No history of hallucination or abnormal ictal sensation before or after sleep.He visited multiple psychiatric clinics and used multiple psychotropic medications only for short periods, Except for Escitalopram 20 mg that he used for 4 years.Escitalopram had improved his mood symptoms slightly but aggravated his sleep condition.He did not have any manic features, psychosis or obsessive-compulsive symptoms.
His past medical and surgical history was insignificant.There was no history of psychiatric illness in his family.
On mental status examination, he looked at his stated age, was slim, cooperative, groomed normally but looked tired.His mood was sad with restricted affect.He conveyed ideas of hopelessness and helplessness, and denied any death wishes or suicidal ideations.No psychotic symptoms could be detected.
We diagnosed him as having Major Depressive Disorder as per Diagnostic and Statistical Manual 5 criteria and Hypnic jerks' movement, and to be investigated to rule out any possible sleep disorder.He was reluctant to change his antidepressant medication due to his previous bad experience of changing his medications.However, he asked if we could help him in regard of his sleep problem instead of mood symptoms.
He was given Zolpidem 10 mg nocturnal as needed for one month.It helped him partially, and could sleeps for 2-3 hours/night continuously, but started to complain from headache when he wakes up.
He was referred to sleep medicine clinic to rule out any possible sleep disorder.Polysomnography done and showed no abnormal event noted during sleep.His physician has recommended him to continue on the same medications.The patient was screened by neurologist for any possible neurological diseases.There was no history of change the level of consciousness or any frothing at the mouth or up rolling of the eyeballs or loss of sphincters control or any abnormal involuntary movements during daytime and other specific neurological diagnosis has been excluded.The diagnosis of Intensified Hypnic jerk movement was confirmed, and we started him on Clonazepam 0.5 mg po at bed time.
On regular follow-up, in one month he showed dramatic improvement in his condition, and the Hypnic jerks movement disappeared completely at night times.Interestingly, he continued to experience the hypnic jerks when he tries to get day naps.
The Depressive symptoms disappeared as well and we discontinued Escitalopram 20 mg and continued on Clonazepam 0.5 PO at bedtime as needed and another 0.5 mg po for day naps if it's required.
The patient completed 2 years on this regimen with no recurrence of mood or sleep symptoms and he did not develop tolerance on clonazepam.The future plan as we agreed with the patient to take off clonazepam gradually to give him trial off medication.

Discussion
Hypnic jerks are a common physiological phenomenon, and their course is usually benign and resolving without any neurological sequel.They are actually classified within Section VII of the ICSD-2, which includes ''isolated symptoms, apparently normal variants, and unresolved issues,'' frequently occurring in normal people and at any age [5].However, recent studies suggest that hypnic jerks may be a characteristic of certain illness, are more prevalent with chronic health conditions that interrupt sleep, and may be mimicked by other movement disorders.It is important to identify differential diagnosis, including nocturnal seizures, nonepileptic seizures, other parasomnias, hyperekplexia, RLS, PLMS, excessive fragmentary myoclonus, and psychiatric diagnosis [3].
The intensified hypnic jerk is primarily based on the patient's history and clinical examination.Polysomnography is helpful in ruling out other sleep disorders.Though an adequate explanation and reassurance may be sufficient, some patients may require a small dose of clonazepam (0.5-1 mg at bedtime) to ameliorate the symptoms on a short-term basis [5].

Conclusions
Hypnic jerk is a common sleep-related movements, and it is a benign condition in most of the cases.However, it can cause significant sleep disturbances, daytime fatigue and led to a significant reduction in the quality of life and put the patient at the risk of having Major depressive disorder.It can be managed through education, lifestyle modifications, and, in severe case Clonazepam is very helpful with precaution of development of tolerance.
Human subjects: Consent was obtained or waived by all participants in this study.Imam Mohammad Ibn Saud Islamic University issued approval 538/2023.Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work.Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work.Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.